This invention relates to a portable security lock for doors. The lock is detachable from any door such that it can be carried to any location where a portable door lock might be needed, e.g. a hotel room door, or any room door not equipped with a permanent locking mechanism.
In some respects, structures of the present invention are similar to portable door locks shown in U.S. Pat. No. 1,074,230 to H. Wiseman, U.S. Pat. No. 1,176,069 to A. Lockhead, U.S. Pat. No. 831,235 to J. Nash, U.S. Pat. No. 618,844 to C. Corey, and U.S. Pat. No. 4,169,619 to J. McCracken. A distinguishing feature of the present invention is a door keeper element formed with an arcuate cam surface centered around a point offset slightly from the swing axis of the keeper element, such that swinging movement of the door keeper element causes the arcuate cam surface to move angularly along the door surface to a wedged condition.
The wedge feature of the newly invented lock compensates for slight differences in door-jamb relationships, e.g. door thickness variations or variations in positionment of the strike plate in relation to the door outer face. The portable lock can be used wherever a portable door lock might be needed without fear that the lock might not fit onto a particular door.
Another advantage of the wedge construction is that a tight fit is obtained between the doorkeeper element and the door face. This avoids any rattle or play between the door and keeper element, such as might lead to dislodgement of the portable lock or a feeling of uneasiness (unsafeness) on the part of the user.
The door keeper does not damage the door structure. The cam accommodates variations in the door strike plate structure and the inside face of the door dimension. The lock does not engage the door trim and is useful independently of the trim structure shape.